Safety device for a hollow medical needle

ABSTRACT

Method, system and device involving a needle device with a needle safety element with improved stable structure. A frame can surround the needle safety element to provide added stiffening of the needle safety element. The frame can include stays extending laterally of the needle safety element. The needle safety element with the frame can be slidably located on a needle and in a catheter hub in a ready to use position and be removable from the catheter hub in a protective position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation application of Ser. No. 13/257,572, filed Sep.19, 2011, which is a national phase application under 35 U.S.C. §371 ofPCT Application No. PCT/EP2010/002757, filed May 5, 2010, which claimsthe benefit of German application No. 10 2009 020 061.4 filed May 6,2009, the contents of which are expressly incorporated herein byreference.

FIELD OF ART

The present disclosure relates to a needle safety device.

BACKGROUND

A needle safety device of this kind is known from WO 99/08742 and EP 1363 690, wherein a clip made of sheet metal is provided as a needlesafety element in which two resilient arms extend from the proximal rearwall in a distal direction and intersect. In the ready position, bentdistal ends of the arms, which are opposite each other, abut on theneedle shaft, and in the protective position they cover the needle tip.Such a needle safety element can be used in connection with a catheter,as known from WO 99/08742, wherein the needle safety element is held inthe catheter hub until the needle is displaced so far out of thecatheter that a radial projection on the needle shaft engages with theproximal rear wall of the needle safety element, whereupon the needlesafety element is withdrawn from the catheter hub with the needle.Likewise, this known needle safety element can also be used without acatheter device, as shown for example in EP 1 363 690. Additionally,from EP 1 363 690, the combination of the needle safety element with asleeve is known. In the protective position, the proximal rear wallengages the radial projection of the needle shaft via the sleeve.

As the needle shaft extends between the intersecting arms of the needlesafety element, the arms are formed relatively narrow in the middleportion. In the protective position, in which the needle safety elementis positioned freely at the needle tip and the arms are no longer guidedthrough the needle shaft, a lateral displacement of the arms of theneedle safety element can occur during handling.

SUMMARY

It is an object of the present method, system and device to provide aneedle safety element of the type described above such that itsprotective function is improved and it has a more stable structure.

According to the present method, system and device, stays extendlaterally from the two arms of the needle safety element approximatelyparallel to the needle shaft, wherein the stays are joined at theproximal end to the proximal rear wall and to each other at the distalends by a bracket extending transversely to the needle axis. In thisway, a stiffening of the needle safety element results in which the armsof the needle safety element are prevented by the lateral stays frommoving away laterally from the needle.

Preferably, the bracket can be provided at the distal ends of the staysat least on one side with a shoulder for forming a cap shape, forachieving further stiffening in the distal end area.

Additionally, the edge of the shoulder can have an extension in theproximal direction at least on one side, for limiting radialdisplacement of one of the arms, wherein this extension furthercontributes to stiffening of the structure.

For stiffening a lateral stay, at least one of the stays can be providedon at least one side with an enlargement.

Hereby, a lug extending in the peripheral direction can be formed atleast on one side of at least one of the stays in the middle portion ofthe stay, for stiffening the stay.

When a safety element is provided that has radially protruding portionsat the proximal and distal ends, the lugs expediently extend in theperipheral direction into the free region between the radiallyprotruding portions of the needle safety element, so as not to enlargethe contours of the needle safety element in a front view of the safetyelement.

For joining the lateral stays to the proximal rear wall of the needlesafety element, lugs can be provided at the lateral stays or at theproximal rear wall. It is also possible to provide at least one stayintegral with the proximal rear wall.

Expediently, the frame formed by the lateral stays, the bracket at thedistal end and the proximal rear wall, which frame is located around themovable arms of the safety element, is formed from a thin metal sheet bypunching and bending; however, it is also possible to assemble aplurality of parts to obtain such a configuration.

Advantageously, a needle safety element having intersecting arms isused; however, a needle safety element can also be surrounded by a framewhose two arms do not intersect and extend on opposite sides of theneedle shaft along the same.

A contribution to the stiffening of the stays is for these to have abent cross-section or edges bent inwards. Additionally or alternatively,the stays can be provided with stiffening ribs extending longitudinally.

For engagement of the needle shaft with the proximal rear wall, crimpingof the needle shaft with at least one resulting radially protrudingbulge or another radial protrusion attached to the needle shaft, forexample a bead, can be provided, wherein a sleeve can also be providedat the needle shaft between proximal rear wall and radial protrusion.Here, the sleeve can either be fixedly connected to the needle safetyelement and thus formed as part of the needle safety element, oralternatively it is not fixedly connected to the needle safety elementand is merely arranged loosely on the needle at the needle shaft betweenneedle safety element and radial protrusion. Here, in the protectiveposition, the edge of the opening in the proximal rear wall of theneedle safety element engages the radial protrusion at the needle shaftvia the sleeve.

In the case of a needle shaft without a radial projection, the openingin the proximal rear wall of the needle safety element or the sleevefixed thereto can engage with the needle shaft in the protectiveposition by clamping when the safety element is canted or tilted inrelation to the needle shaft. The needle safety element is thenpreferably formed with further suitable clamping areas, which engagewith the needle shaft to provide additional clamping in the protectiveposition. Even when the needle shaft has a radial protrusion, the needlesafety element can also have corresponding clamping areas. Forincreasing the secure grip in the protective position, in a clampingembodiment an additional tether can be provided between needle safetyelement and needle hub.

Expediently, the bracket of the frame is provided with a bore forreceiving the needle in the ready position; however, the bracket canalso be formed such that it has only an approximately semicircularrecess along an edge, in which recess the needle is guided.

An aspect of the present disclosure refers to a needle safety assemblycomprising:

-   -   a needle safety element slidably mounted on a needle shaft        having a needle tip; the needle safety element comprising a        proximal wall having an opening and a movable distal wall;    -   a frame surrounding, at least in part, the needle safety element        comprising a first stay and a second stay connected to a bracket        and to the needle safety element.

In such an embodiment the needle safety assembly can comprise further:

-   -   a first lug connected to the first stay along a first axial        position on the first stay and extends radially relative to the        needle shaft.

Further the needle safety assembly can comprise:

-   -   a second lug connected to the second stay along a first axial        position on the second stay and extends radially relative to the        needle shaft.

In such an embodiment the first axial position on the first stay can belocated, relative to the needle shaft, at a different position than thefirst axial position on the second stay.

Preferably the first lug extends radially so that an end edge of thefirst lug is closer to the second stay than the first stay.

Further the bracket and the two stays are unitarily formed preferably.

It is of advantage that safety element comprises a first arm and asecond arm.

The present method, system and device also comprise combinations of thefeatures described.

Further aims, advantages, features and application options of thepresent method, system and device follow from the following descriptionof the embodiments with reference to the drawing. Hereby, all thefeatures described and/or represented by the drawing form the subjectmatter of the present method, system and device in themselves or in anymeaningful combination, independently of their summary in the claims andthe back-references thereof.

BRIEF DESCRIPTION OF THE FIGURES

The present method, system and device are explained in more detail belowwith reference to the drawing, in which:

FIG. 1 shows a side view of a needle safety element having twointersecting arms in the protective position without lateral stays,

FIG. 2 shows a view of the needle safety element from below in FIG. 1,

FIG. 3 shows a longitudinal section through the needle safety element inthe protective position with a lateral stay,

FIG. 4 shows in the same view as FIG. 3 an embodiment with a cap-shapedbracket,

FIG. 5 shows an embodiment with a cap extended on one side,

FIG. 6 shows an embodiment with a lug on one side of each stay, whereinthe arms are in the ready position,

FIG. 7 shows a plan view from above in FIG. 6,

FIG. 8 shows a perspective view of the bracket shape in FIGS. 6 and 7without the needle safety element,

FIG. 9 shows a plan view of the embodiment according to FIG. 8,

FIG. 10 shows a perspective view of a further embodiment in theprotective position,

FIG. 11 shows a view of the embodiment in FIG. 10 from below, and

FIG. 12 shows a perspective view of the needle safety device inside aprotective needle cap.

DETAILED DESCRIPTION

FIG. 1 shows a hollow medical needle 1. The medical needle 1 comprises ashaft 1.1 having a portion 1.3 near the needle tip 1.2 having anenlarged diameter in relation to the diameter of needle shaft 1.1, forforming a radial projection. In the embodiment according to FIG. 1, thisportion 1.3 has the form of a crimp of the needle shaft, which isindented on two sides and broadened in the transverse direction.According to another embodiment, the portion 1.3 can also only have theform of a bead on the needle shaft, having a predetermined distance fromthe needle tip in accordance with the length of the arms of the safetyelement 2. A further embodiment of the portion 1.3 can also be only abulge or a crimp on only one side of the needle shaft 1.1, or be formedby a metallic coating on the needle shaft.

On the needle shaft 1.1, there is arranged a needle safety element 2formed from thin sheet metal, which has a proximal rear wall 2.1 havinga bore 2.2, through which the needle shaft 1.1 extends displaceably. Thediameter of the bore 2.2 is smaller than the outer diameter of theportion 1.3 on the needle shaft, so the needle safety element 2 cannotbe displaced beyond the needle tip in the distal direction, because theedge of the bore 2.2 in the rear wall of the needle safety elementretains the portion 1.3 with an enlarged diameter. Thus the bore 2.2 inthe rear wall 2.1 of the needle safety element forms an engagement meanswith the needle shaft. Instead of a bore, a sleeve can also be providedat or in front of the proximal rear wall 2.1 of the needle safetyelement 2, through which sleeve the needle shaft 1.1 extends and whoseinner diameter is smaller than the outer diameter of portion 1.3 havingthe enlarged diameter, so that by means of the sleeve, the place ofengagement of needle 1 and safety element 2 in FIG. 1 is displaced tothe left or in the distal direction.

In the embodiment of the needle safety element 2 in FIG. 1, tworesilient arms 2.3 and 2.4 extend from the proximal rear wall in adistal direction, wherein the arms are preferably of different lengthand intersect in the middle portion. Bent wall portions 2.5 and 2.6 areprovided at the distal ends and are formed onto the straight portions ofthe arms 2.3 and 2.4 by means of an elbow-shaped portion 2.7 which isbent outward. These elbow-shaped portions 2.7 serve for engagement witha catheter hub when the needle safety device is used in connection witha catheter device. At the free ends, the two arms 2.3 and 2.4 each havea bent end portion 2.8, which abuts resiliently on the needle shaft 1.1in the ready position, and contributes to a reduction in friction bymeans of the bend.

Although the needle safety element 2 is shown formed from a single sheetof spring steel, it is also possible to assemble different parts of theneedle safety element to give a needle safety element by welding,brazing or beading. Here, different materials can also be used forindividual parts, for example plastic and metal.

FIG. 1 shows the protective position of the needle safety element 2wherein the portion 1.3 having an enlarged diameter which can be formedas a radial projection, abuts on the edge of the bore 2.2 in theproximal rear wall 2.1. The longer arm 2.3 overlaps the needle tip 1.2by means of the wall portion 2.6. The distance between needle tip 1.2and portion 1.3 can also be configured smaller, so that the shorter arm2.4 also overlaps the needle tip.

As FIG. 2 shows at 2.41, the arms 2.3 and 2.4 adjacent to the proximalrear wall 2.1 have a widened portion which merges into a narrow portionalong which a stiffening rib 2.3 a or 2.4 a is formed. The needle 1extends between these two narrower, intersecting, laterally distancedportions. In the distal end portion, the arms 2.3 and 2.4 again havewidened portions, as FIG. 2 shows at 2.32, wherein the distal wallportions 2.5 and 2.6 have a lesser width dimension than the arms 2.3 and2.4 in the proximal area adjacent to the rear wall 2.1.

As shown in FIGS. 1 and 3, the bent end portion 2.8 of the arm 2.4 abutslaterally on the needle tip 1.2, so that the safety element 2 cannot betilted in the counter-clockwise direction relative to the needle shaftin FIGS. 1 and 3. To prevent tilting of the safety element 2 in theclockwise direction relative to the needle shaft in the protectiveposition, the transversely-extending edge 2.32 a (FIGS. 2 and 3) of thewidened portion 2.32 adjacent to the elbow-shaped portion 2.7 ispositioned in such a way that this edge 2.32 a abuts on the needle inthe protective position of FIGS. 1 to 3. If the distal end of the arm2.4 also covers the needle tip 1.2 in the protective position, then thecorresponding edge 2.42 a (FIG. 3) of the widened portion adjacent tothe elbow-shaped portion 2.7 can also be used for preventing tilting ofthe safety element 2 in relation to the needle shaft.

In the proximal area of the needle safety element 2, lateral stays 3 aand 3 b (FIG. 8) are fixed, which extend along both sides of the arms2.3 and 2.4. In the embodiments shown, bent and protruding lugs 2.9(FIGS. 1 and 2) are formed at the proximal rear wall 2.1 in the distaldirection, wherein the proximal ends of the stays 3 a and 3 b are fixedonto these lugs 2.9 by adhesion, laser welding or resistance weldingsuch that they form a unit with the safety element 2. Instead of thelugs 2.9, corresponding lugs can also be formed on the proximal ends ofthe stays which can be joined to the proximal rear wall 2.1 of theneedle safety element after bending.

Thus the present method, system and device comprise a needle safetyelement having preferably two intersecting arms having two stays whichare spaced apart from each other and are fixedly joined to the proximalend of the needle safety element. In one embodiment, the fixing locationis distal of the proximal wall by means of lugs extending from theproximal wall in a distal direction. In another embodiment, the fixingat the proximal wall takes place by bending over the two proximal endsof the two stays and fixing the bent ends directly at the proximal wall.

According to another embodiment, at least one of the stays 3 a and 3 bcan be formed by means of punching of a sheet metal integral with theproximal rear wall of the safety element 2.

The stays 3 a, 3 b likewise preferably consist of sheet metal, and theyare joined to each other at the distal ends by a bracket 3 c, whichextends transverse to the needle 1 and is preferably provided with athroughbore 3 c 1 for receiving the needle 1. The stays 3 a and 3 b eachhave upper and lower edges 3.8 a and 3.8 b (FIG. 3), so the twointersecting arms 2.3 and 2.4 are more visible with respect to theirfunction.

The bracket 3 c with the two lateral stays 3 a and 3 b, which can bedenoted as a protective band or frame 3.9 in FIG. 3, prevents lateraldisplacement of the needle safety element 2 relative to the needle shaft1. As can be seen in FIG. 1, the safety element 2 can become displacedon the needle section 1.3, so the distal wall areas 2.5 and 2.6 can moveout of the protective position somewhat, i.e. somewhat out of the planeof FIG. 1. By means of the two spaced-apart lateral stays 3 a and 3 b, arelative movement between needle tip 1.2 and distal wall portions 2.5and 2.6 is prevented—if such a relative movement occurs at all—becausethe needle 1 is fenced in the space defined by the two stays and the twoarms. Because the longer arm 2.3 cannot be displaced laterally ordownward, the possibility of the needle tip becoming exposed by alateral movement is prevented, as the protective element 2 is moved intothe protective position. Thus the present method, system and devicecomprise a protective element having two intersecting arms and aprotective band or frame which has two spaced-apart stays joined to theprotective element in the proximal area and joined to the bracket in thedistal area, for preventing deflection of the two stays against eachother or away from each other. The joining of the two stays also limitsthe displacement of the safety element by limiting the movement of theneedle tip to an area which is defined by the two stays and the twoarms, called a needle containment space. In certain embodiments, thearms can be generally parallel or intersect as shown.

To stiffen the stays 3 a, 3 b formed from a metal strip, stiffening ribs3 a 1 and 3 b 1 are formed along these in the wall areas. Alternativelyor additionally to this, the metal strip of the stays can be formed froma thicker sheet material. In a cross-sectional view, the stays 3 a, 3 bthemselves can be slightly bent or have edges bent inward so that thestiffness of these stays is improved. In the cross-sectional view, theflat extension of the stays 3 a, 3 b extends transverse to the flatextension of the arms 2.3 and 2.4, as shown in FIG. 3.

In a plan view of the embodiment in FIG. 3, the bracket 3 c forms anapproximately rectangular frame with the proximal rear wall 2.1 of theneedle safety element and the two stays 3 a and 3 b, wherein the twoarms 2.3 and 2.4 of the needle safety element are able to move insidethis frame. Thus according to an aspect of the present method, systemand device a frame is provided comprising a distal wall (bracket), twostays and a proximal wall within which the two intersecting arms canmove. The safety element is also to be understood as such, having twoarms which can lie in a position radially outside the space or regiondelimited by the frame, and moving into the region delimited by theframe. According to one embodiment, the safety element can have two armswhich start from a position outside the region delimited by the frameand intersect in a position inside the region delimited by the frame.

FIG. 4 shows an embodiment in which the distal bracket 3 c 1 is formedon the upper and lower side by a rounded boss 3.1 in the form of a cap.The rounded cap is preferably provided for avoiding sharp edges. Thisrounded boss 3.1 can also be formed on only one side of the bracket 3 c1. As shown, the two rounded bosses are arranged above and below the twoedges 3.8 a and 3.8 b of the two band-shaped stays. If only one roundedboss is provided, then a device is understood thereby which has a singleboss either above or below the two edges and a straight edge on theother side of the bracket.

In the embodiment according to FIG. 5, the boss 3.1 is provided with anextension 3.2 in the proximal direction on the side opposite the distalend of the longer arm 2.3, and by means of this extension a displacingmovement of the distal end 2.6 of the longer arm is further prevented.For example, when the distal end 2.6 moves upwards in FIG. 5, it willcome to abut on the elongation 3.2 and thus it will be prevented by thiselongation from moving out too far radially from the space or regiondefined by the frame. On the other hand, this elongation 3.2,corresponding in cross-section to the rounded boss 3.1, is configuredwith regard to its length such that the short arm in FIG. 5 can move outupwardly over this elongation 3.2.

FIGS. 6 and 7 show an embodiment in which the stays made from a metalsheet by punching and/or stamping have an enlargement 3.3 on at leastone side in the distal end portion. The enlargement is preferably formedon the side of the distal end of the shorter arm 2.4 and ensuresimproved protection from lateral displacement especially of the distalend of the shorter arm, wherein the proximal elongation 3.2 of the boss3.1 at the side edges abuts on this enlargement 3.3 as shown in FIG. 6.

Depending on the type of cutting die, during production of the guardband or stiffening bracket forming a frame with the rear wall 2.1, thedistal end portion of the enlargement 3.3 can extend into the proximalelongation 3.2 at the cap-shaped bracket. For example, the extension 3.2can extend somewhat upwards such that at least a part of this extension3.2 is covered by the enlargement 3.3 in a perspective view of FIG. 6.This proximal elongation 3.2 can have in the middle portion thereof agap or a parting line in the axial direction of the needle, whichparting line is determined by the metal blank which is used fordeformation after punching by stamping and bending.

Approximately in the area of the point of intersection of the two arms2.3 and 2.4 of the needle safety element, on one side of each stay a lug3.4 a and 3.4 b is formed extending in the peripheral direction, bentsomewhat inwardly toward the needle and adapted to the curve of theelongation 3.2 in the cap portion. The lug 3.4 b is formed on the sideof the stay 3 b on which the shorter arm 2.4 extends, as shown in theplan view in FIG. 7, so that this lug 3.4 b ensures further protectionfrom upward displacement of the arm 2.4 in FIGS. 6 and 7. In acorresponding way, the lug 3.4 a is formed at the lower side of the stay3 a in FIGS. 6 and 7, to prevent the arm 2.3 extending along the stay 3a from downward displacement.

Thus an aspect of the present method, system and device is a protectiveelement having two arms, wherein each arm comprises a portion extendingalong an associated side of the needle shaft. A band or a stay alsoextends on each side of the needle shaft and of the two arms. In oneembodiment, a lug extending in the peripheral direction extends fromeach stay over an associated arm. According to a further aspect of thepresent method, system and device, a protective band or frame isprovided which surrounds a safety element, wherein two spaced-apart lugsare provided which each extend from a stay, and wherein the two lugsextend in the clockwise direction in the view from the proximal to thedistal end.

While FIG. 5 shows the arms 2.3 and 2.4 in the protective position, thearms in FIG. 6 are shown in the ready position, in which the bent endportions 2.8 of the arms abut on the needle shaft which is not shown inFIG. 6. In this position, the elbow-shaped portions 2.7 project furtherupwardly and downwardly over the lateral stays 3 a and 3 b, so that thelugs 3.4 a and 3.4 b offer additional protection from displacement ofthe arms. FIGS. 8 and 9 show the arrangement of the lugs 3.4 a and 3.4 bat the stays without a safety element. In other words, FIGS. 8 and 9show a band-shaped guard 3.9 provided according to an aspect of thepresent method, system and device, wherein the safety element 2 is notshown in FIGS. 8 and 9.

FIG. 10 is a perspective view of an embodiment in which lugs 3.4 a′ and3.4 b′ are formed enlarged in the longitudinal direction of the stays,by means of which the protection from deformation of the needle safetyelement 2 is further improved. Here, a contribution to the stiffness ofthe device is also made by a lug being formed on each side of each stay3 a and 3 b, as shown in FIGS. 10 and 11, wherein FIG. 11 represents aview of the needle safety device from below in FIG. 10. In other words,each stay comprises two lugs extending from each longitudinal edge ofthe stay. As can be seen from FIG. 10, due to the enlargement of thelug, in the proximal direction a shorter distance results between theproximal edge of the lug 3.4 b′ and the widened portion 2.31 of the arm2.3, while on the opposite side, the distal edge of the enlarged lug 3.4b′ lies in the distal direction a shorter distance from the arm 2.4 andoverlaps the same, so that the two arms 2.3 and 2.4 can be displacedupwardly and downwardly to a slighter degree than in the embodiment ofFIGS. 6 and 7.

Thus the present method, system and device comprise an elongation orextension of the lug in a distal and/or proximal direction at theassociated stay, to limit upward and downward displacement of the arm.In other words, the lugs can be configured in the axial direction suchthat they determine the displacement of the arms in the radialdirection.

To achieve this effect, the lugs formed at the opposite stays 3 a and 3b can also be offset to each other in the longitudinal direction, sothat for example in FIG. 10 the lug 3.4 b′ is offset further in thedistal direction relative to the opposite lug 3.4 a′. FIG. 11 shows lugs3.4 a′ and 3.4 b′ offset relative to each other in the longitudinaldirection.

The lugs have rounded corners to avoid sharp edges. Preferably, anarc-shaped transition is formed between the enlargement 3.3 and theshoulder of the lug 3.4 b′, as FIG. 10 clearly shows.

Thus a further aspect of the present method, system and device is asafety means having a band-shaped guard having two lugs along a firstside which are offset in the axial direction, and along a second side,which are also offset in the axial direction.

The stiffening frame made from thin sheet metal by punching and bendingand having the stays 3 a, 3 b, has an approximately U-shaped basic formwith flattened shoulders corresponding to the stays, as can be seen fromFIGS. 8 and 9. The stays 3 a and 3 b provided with lugs, extendingtransverse to the arms 2.3 and 2.4, extend continuously from theproximal end over the distal end of the needle safety element 2 andprovide a stiff frame for the needle safety device.

According to another embodiment, the lugs 3.4 a′ and 3.4 b′ in FIGS. 10and 11 can be formed lengthened in the peripheral direction, so that theedges of the lugs, which lie opposite each other, form a narrow gap onthe upper and lower side of the needle safety device, which gap isformed relatively wide in FIGS. 10 and 11 by the distance of theopposite edges of the lugs 3.4 a′ and 3.4 b′. In other words, the edgeof each lug extending in the longitudinal direction can extend furtherin the direction towards the needle shaft or in the peripheraldirection, so a narrower gap is present between the two opposite edgesof the two lugs 3.4 a′ and 3.4 b′ extending in the longitudinaldirection in FIG. 11.

According to a further embodiment, the opposite lugs 3.4 a′ and 3.4 b′can also be lengthened in the peripheral direction so far that theiredges abut at each other on the upper and lower side or only on one sideand thus overlap or cover the middle portion of the intersecting arms2.3 and 2.4. In such an embodiment, the lugs 3.4 a and 3.4 b provide aclosed or approximately closed cross section together with the stays 3 aand 3 b in a sectional view of the needle safety device. Hereby, thelugs surrounding the needle safety element 2 extend into the free spaceO (FIG. 1) between the proximal and the distal ends of the needle safetyelement such that they lie inside the elbow-shaped portions 2.7 of thearms of the safety element in a front view of the needle safety element,at least when the arms are in the ready position, in which they arepre-stressed in a radially outward direction by the needle shaft, asshown in FIG. 6. The peripheral line of the elongation 3.2 is alsoformed together with the cap-shaped bracket such that it lies radiallyinside the elbow-shaped portions 2.7 of the arms in the ready position,as shown in FIG. 6. In this way, the radial outer dimensions in the areaof the cap and of the lugs correspond approximately to the outerdimension of the proximal rear wall 2.1. Preferably, the cap and thelugs have a smaller profile than the proximal rear wall 2.1 in the frontview from the left in FIG. 6.

In the embodiment of FIG. 6, each lug 3.4 a and 3.4 b can also extendalong approximately half of the periphery up to the opposite stay 3 a or3 b, so that in this way too, a closed cross section is provided in themiddle portion of the needle safety element 2.

According to a further modification, the needle safety element can alsobe formed with arms 2.3 and 2.4 extending approximately parallel to eachother, wherein the two arms can be bent in the middle portion preferablysomewhat inwardly toward the needle, so that in this area the lugs 3.4 aand 3.4 b can overlap the arms of the safety element further inwardly,while the elbow-shaped portions 2.7 provided for engagement with acatheter hub are exposed. In the embodiments shown, in the viewaccording to FIG. 1, by means of the intersecting arms 2.3 and 2.4 afree space O is provided in their middle area between the articulationportion of the arms at the proximal rear wall 2.1 and elbow-shapedportions 2.7, into which the lugs 3.4 a and 3.4 b can extend. This freespace O can also be formed by deflection of non-intersecting butopposite arms.

The needle safety element 2 described is preferably formed by punchingand bending of a thin metal strip so that altogether the smallestpossible overall dimensions are achieved. In practice, the safetyelement 2 has for example a longitudinal dimension of approximately 8 mmand a radial dimension of approximately 3 mm. In a corresponding way,the frame around the two arms is formed by punching and bending of thesheet metal such that the overall dimensions of the needle safety deviceare not increased by a remarkable amount. It is clear that the sameconfiguration can be achieved using a plurality of components or partswhich are assembled to obtain a safety element having a band-shapedguard for improving stability. The plurality of single parts can beformed from different metals or materials or from a plastic-metalcompound.

According to a modification, the cap-shaped bracket 3 c can also bejoined to the stays 3 a and 3 b by adhesion or welding. The bracket canalso be formed such that it extends under or over the needle shaft,wherein for example an approximately semicircular recess can be formedin the bracket for guiding the needle shaft in the ready position. Abracket having a bore for the passage of the needle as shown ispreferred.

When the elbow-shaped portions 2.7 have another function than engagingwith a catheter hub, these arc-shaped portions 2.7 can also have anothershape. For example, they can be bent sharply, to form an edge actingoutwardly. It is also possible to form this arc-shaped portion 2.7flattened, so that it does not protrude or hardly protrudes over theperiphery of the cap-shaped bracket 3 c.

Instead of sheet metal, another material can also be used, which whenhaving small dimensions is correspondingly formable to form a needlesafety device having small dimensions in this way.

The small dimensions of the needle safety device made of sheet metalalso allow the needle safety device arranged in the ready position on ahollow medical needle in the proximal area of the needle shaft to becovered by a conventional needle safety cap 5, which cap is placed on aneedle hub 1.4, as FIG. 12 shows, without the risk of the needle safetydevice being moved on the needle shaft during removal of the needlesafety cap 5.

Preferably, grooves extending lengthwise are formed onto the needlesafety cap 5 and distributed over its inner periphery, and by means ofthese grooves the needle safety cap is held on the needle hub 1.4 onwhich corresponding radially projecting ribs 1.5 are formed distributedover the periphery. Due to the small radial dimensions of the needlesafety element 2 having the stiffening frame 3 a to 3 c, there is norisk that the needle safety cap 5 could contact the needle safetyelement 2, so the inner and/or outer surfaces of the needle safety cap 5can also be formed corrugated.

If the described needle safety device is made of plastic, it has largerdimensions, wherein a frame formed as described is provided in the sameway around the resilient arms of the needle safety element.

Instead of two bent distal end walls of the safety element 2, a safetyelement can also be provided wherein only one arm has a bent distal endwall, which overlaps the needle tip in the protective position.

The invention claimed is:
 1. A needle safety assembly comprising: aneedle safety element slidably mounted on a needle shaft having a needletip; the needle safety element comprising: a proximal wall having anopening; a moveable distal wall; and two movable arms which do notintersect and extend along opposite sides of the needle shaft; a framesurrounding, at least in part, the needle safety element comprising: afirst stay and a second stay connected to a bracket; and lugs formed onthe proximal end of the stays.
 2. The needle safety assembly accordingto claim 1, wherein the stays are joined to each other at the distalends by the bracket.
 3. The needle safety assembly according to claim 1,wherein the stays extend laterally from the two arms of the needlesafety element approximately parallel to the needle shaft.
 4. The needlesafety assembly according to claim 3, wherein the bracket extendstransversely to the needle axis.
 5. The needle safety assembly accordingto claim 1, wherein the stays are joined at the proximal end to theproximal rear wall.
 6. The needle safety assembly according to claim 1,wherein the stays of the frame are fixedly connected at their proximalends with the proximal wall of the needle safety element.
 7. The needlesafety assembly according to claim 1, wherein at least one stay isintegral with the proximal wall.
 8. The needle safety assembly accordingto claim 1, wherein the bracket and the stays are unitarily formed. 9.The needle safety assembly according to claim 1, wherein the frameformed around the moveable arms of the needle safety element by thelateral stays and the bracket s formed from thin sheet metal by punchingand bending.
 10. The needle safety assembly according to claim 1,wherein the needle safety element comprises two resilient arms extendingfrom the proximal wall in the distal direction, both arms being providedwith a distal end portion opposite each other, the moveable distal wallbeing provided on the distal end portion of each of the resilient arms.11. The needle safety assembly according to claim 10, wherein the distalend portions of the arms abut on the needle shaft in the ready position.12. The needle safety assembly according to claim 10, wherein the distalend portions of the arms cover the needle tip in the protectiveposition.
 13. The needle safety assembly according to claim 1, whereinthe stays have a curved cross-section or have inwardly bent edges in thesectional view.
 14. The needle safety assembly according to claim 1,wherein the bracket has a bore through which the needle extends in aready position.
 15. The needle safety assembly according to claim 1,wherein the needle shaft is provided with a radial projection, which inthe protective position engages with the proximal wall of the needlesafety element.
 16. The needle safety assembly according to claim 1,wherein the radial projection in the shaft of the needle is formed as acrimp or as a bead or as a metallic coating.
 17. The needle safetyassembly according to claim 1, wherein the stays are provided withstiffening ribs extending lengthwise.
 18. The needle safety assemblyaccording to claim 1, wherein the needle safety element s held in acatheter hub until the needle is displaced so far out of a catheter thatthe radial projection on the needle shaft engages with the proximal wallof the needle safety element.
 19. The needle safety assembly accordingto claim 1, wherein the distal end portions are formed on arms by meansof elbow-shaped portions which are adapted to engage with a catheter hubwhen the needle safety device is used in connection with a catheterdevice.